Ohio fireflies back in big way

In this one hour exposure photo taken June 22, 2009 and provided by Steve Irvine, fireflies fly in front of his home in Big Bay, Ontario in Canada. A childhood rite of passage _ catching fireflies in Mason jars and watching them glow _ could be fading along with the dog days of summer. Scientists are busy analyzing a summer's worth of observations of the mesmerizing insects collected by a network of backyard volunteers in hopes of verifying whether anecdotal evidence suggesting the luminous insects are on the decline is correct, and if so, what's behind their shrinking populations. (AP Photo/Courtesy Steve Irvine) NO SALES(Photo: Steve Irvine, AP)

This summer of 2014, frequently cool, sometimes even chilly, has not been ideal for taking a dip in the pool or hanging out at the beach, but the Lampyridae family certainly isn't complaining.

About two dozen species of fireflies — members of the Lampyridae family — call Ohio home, and despite years of concern about their supposedly declining numbers in the Buckeye State, they're back in a big way this summer, depending on where you live.

"We started to see an increase last year, and they've been on the rise again this year, and my prediction is we'll see even more next year," said Dr. David Shetlar, an entomologist with The Ohio State University Extension.

Credit the weather, for starters.

"In general, the season started later for insects this year and is extending later. It's related to the cool spring and summer, and the cool nights in particular," said Dan Herms, professor and chair of the Department of Entomology at Wooster's Ohio Agricultural Research and Development Center.

In Ohio, fireflies typically start flashing in early June, peaking around the Fourth of July. But this summer, particularly in rural areas across the state, fireflies have remained active into the middle of August.

"You have to look at the full life cycle of the insect. The larvae feed on snails and slugs, and because of the weather, there's been plenty of those," Shetlar said.

While temperatures this past June were normal to actually a bit warmer than average in Ohio, they turned sharply colder than normal in July and are so far trending that way in August as well. But in attempting to explain the ups and downs of insect populations, such as those of the firefly, weather trends go only so far.

"It's all about the unintended consequences of things. Suburban areas use way too much mulch, which I chide them for, but that results in more slugs to feed on the fungi in the mulch. We also overwater our flower beds," Shetlar said.

"Many corn and soybean fields are using no-till (cultivation) now and are starting to see more slugs eat the seedlings as they come out. Agronomists are trying to adjust that."

For years now, however, the general, anecdotal consensus has been that fireflies are on the decline, with increased pesticide use getting most of the blame.

While fewer chemicals in their habitat can only be beneficial for fireflies, "it's an oversimplification to make that tie, because then the environmental groups always claim it's because of the pesticides, when the real regulation factor is the amount of snails and slugs," Shetlar said.

Still, there's no question that fireflies are fewer in number in urban areas, while they can found in abundance in, say, the Amish counties of north central Ohio, where pesticide use has generally been lower than elsewhere in Ohio for many years. And they used to be more abundant in the cities than they are today.

"There are declining numbers of fireflies due to urbanization. Ecologically sustainable gardening and habitat diversity can certainly help," Herms said.

"We used to live near woods and this huge goldenrod field and had spectacular displays. Here, in the city of Wooster, there aren't as many as we're used to, and certainly not as many as I remember growing up."

Firefly clinging to the underside of a leaf.(Photo: Submitted)

The jury remains out on whether fireflies are affected by light pollution. They're not attracted to bright lights the way other insects such as moths are, but artificial lighting can disrupt fireflies' mating behavior. And urban areas have both more light pollution today and, because of a growing abundance of impervious surfaces, fewer snails and slugs.

In addition to being a popular favorite with children, as well as adults, for their ability to generate light without heat, or bioluminescence, fireflies exhibit a flashing behavior that's far more complicated than most of us realize.

"They have different kinds of flashes, at different heights, and can be ascending or descending. One species that's up high a lot of people miss. It's at about the middle of the tree line and has a weaker flash. Others are about chest-high and others probably lower than four feet; those are the ascending ones," Shetlar said.

There also are three or four firefly species in Ohio that don't flash at all.

The website Firefly.org is reporting an increased incidence of firefly sightings this summer, particularly in the South. Boston's Museum of Science began a program called Firefly Watch in 2008, which now has 5,000 people in the U.S. and Canada reporting their firefly sightings, as well as posting their firefly poems, some better than others.